... That got me to wondering. Is the I formation of any use at all in league doubles? I never see it in mixed or ladies 3.5/4.0. What did these ladies do wrong that caused it to be so ineffective?

We use Ausie a lot with generally good results. We rarely use the I. Ausie seems easier (but maybe that's just because we use it more). On the other hand, I was watching the men's 4.5 final at a tourney a couple weeks ago and one team use the I almost all the time.